It didn't take long for the leaders to come around and lap the archaic two-man cars.  Decades ago I was driving north on California's Hwy 1 (south of Carmel) and came up fast  behind a horse-drawn Amish buggy.  The buggy took up its entire lane and was moseying along at walking speed..  After a scary moment I got safely around.  I think Shirley, MacAllister, and the other "fast guys" in Group 1 must experience similar moments when they come up behind these slow movers.